A U.S. maritime alert, active through 13 January, warned of “the possibility of Iranian action against U.S. maritime interests in the region”, specifying that “U.S. commercial vessels are advised to exercise caution and coordinate vessel voyage planning for transits of the Persian Gulf, Strait of Hormuz, Gulf of Oman, North Arabian Sea, Gulf of Aden, and Red Sea with NCAGS (U.S. Fifth Fleet Naval Cooperation and Guidance for Shipping)”.